Ice can form on the surfaces of an aircraft in flight when water droplets impinge and freeze on the aircraft surfaces. The accretion of ice on certain aerodynamic surfaces can reduce the performance and handling characteristics of the aircraft. For example, ice accretion on the leading edges of the wings can alter the cross-sectional shape of the wings which can disrupt the flow of air over the wings, resulting in reduced lift capability of the wings, increased aerodynamic drag, added weight, and increased stall speed of the aircraft.
Current methods of addressing ice accretion on the leading edges of airfoils include the use of inflatable deicing boots mounted on leading edge surfaces. When ice has accumulated on a leading edge, the boots may be inflated with compressed air causing the ice to crack. Air flowing over the wings blows the ice off the wings, after which the boots are deflated to return the leading edge to its pre-inflated shape. Although generally effective, deicing boots add cost, complexity and weight to the aircraft.
Another method of addressing ice accretion on leading edges involves the use of a bleed air de-icing or anti-icing system in which hot air is bled from gas turbine engines of an aircraft. The bleed air is routed through spray tubes extending along the interior of the leading edges and is discharged in a manner to heat the wing surfaces. The bleed air may be periodically activated in a manner to maintain the surfaces of the leading edges above freezing to prevent the formation of ice, or to melt the ice to an extent that air flowing over the wings blows the ice off the wings. Although effective in addressing ice accretion, the extraction of bleed air from the engines reduces engine performance. In addition, the spray tubes and other hardware of a bleed air system add to the cost, complexity and weight of the aircraft.
As can be seen, there exists a need in the art for a system and method for reducing ice accretion on an airfoil that reduces the need for ice protection hardware (e.g., deicing or anti-icing system hardware).